What is a Software Development Life Cycle (SDLC)? An Overview
Many software development methodologies are used today, the main ones being the Waterfall method, Agile models, V-shaped model (the validation and verification software development process), among others. They all have their pros and cons, however, we will explore a common understanding of the software building process, which includes universal processes that are used by developers. These methods are more like tools and structures that developers can use to better deliver a software project.
Definition and meaning of a Software Development Life Cycle?
SDLC is a software life cycle process of a software project followed by a company from start to finish, to conceptualise, develop, and maintain a software application.
Why is an SDLC important?
To have a detailed plan and blueprint for the product development.
To adhere to a predetermined time frame for delivering the final product.
To not go overboard with the budget set for development.
To define the deliverables at every sprint/stage of development.
To encompass the technical aspects with the creative and operational side.
To create a structured approach for various teams.
To improve broken processes and inefficient workflows.
Proper flow of data from one level to another.
To improve the quality and reliability of your software products.
For creating a systematic approach for project tracking, visibility of all aspects and control over them.
What are the different stages of a Software Development Life Cycle?
- Requirements collection, planning and analysis
The very first and foundational stage of SDLC involves the participation and inputs of all the stakeholders in the processes, including developers, business owner (client requirements), strategists, sales and marketing executives, quality assurance and control teams, IT and systems managers, and other vital roles.
Project leaders are required to identify the business objectives, and figure out the time, budget, resources, and roadmap for the entire project. Important criteria such as the client’s end goals, customer’s expectations, and the purpose of the product should be defined and ambiguous processes should be eliminated in this phase so that there are no hiccups in the later stages. The more precise the planning, the better the results at each sprint.
After the requirements collection is done, the project leaders (with inputs from other teams) shall analyse the practical implementation and feasibility of the ideas and needs, after which a Software Requirement Specification document is created which the developers are expected to follow.
After requirements gathering and analysis, begins the software design stage which starts with a design specification plan which also contains defining overall system architecture.
High-Level Design contains factors such as the overall description/architecture of the application, including description and functionality of each module, interface relationship and dependencies within modules, created by Solutions Architect with inputs from the design team, review team and client team.
Low-Level Design consists of functional logic/ details of the modules created by developers which are fleshing out the details of the high-level design documents. Here the designers create
data structures and algorithms of the modules are designed and documented, including class diagrams with the methods and relations between classes and program specs, details of the interface, database tables, type and size.
Programmers then choose their preferred programming languages and start the coding process which is the longest phase of SDLC, however it can be planned in sprints, units and modules for better execution. The design document is converted into source code by developers who usually build their codebase with the help of existing libraries, compilers and interpreters, among other tools and frameworks.
The code is continuously reviewed and corrected for producing high-quality apps/websites, all the while following original guidelines in the design document. Agile methodologies are used to reduce the time required to code efficiently with sprints and iterations. The goal is to create software that can be easily used and understood by the end-user who may be the general public, organizations or stakeholders within businesses. The final manifestation should be useful once the coding is complete.
All the code developed during the coding phase is put to test in the testing phase with the help of various test cases and by following the test plan instructions in a pre-established testing environment. QA and testing teams are responsible for finding bugs, defects and malfunction in the software. The main focus is on investigation and discovery.
Usually, the process is divided into four types of testing, System Testing, Integration Testing, Acceptance Testing, and Unit Testing, however, there are numerous other subtypes of testing.
The components that need to be planned are test planning, test case design and development, test environment set-ups and finally the test execution. Automated testing is prevalent but it too has to be detailed as mediocre tests don’t cut it these days, thus retesting, regression testing is done until the software is ready to fulfil all customer expectations.
This is the stage where the product is presented to the initial users in the production environment or first UAT (User Acceptance Testing). Once the deployment takes place, user feedback is obtained and the corrections are made. If no bugs or defects remain, the software is released to the end-users after solving any technical problems of deployment.
- Maintenance and updates
Once the users start using the software, a few activities need to be carried out regularly. These include fixing bugs and glitches, deploying updates and enhancements to the software so that the users experience a continuous high-quality performance from the software. Tools for Application performance monitoring (APM) are useful for maintenance. New features are added based on extensive internal and external feedback from sales, operations, marketing teams as well as customers.
There’s no need to always follow a sequential SDLC as these days Agile/ Lean methodologies allow for incremental development as well. Whether in a linear, iterative or any other model, certain stages are common and necessary. Change in requirements may occur at any stage, requiring developers to be flexible.